Temporary anti-drainback valve opener for an oil filter assembly

ABSTRACT

An oil filter for an internal combustion engine lubrication system has an anti-drainback valve that is temporarily held open with a quantity of special grease during the initial filling of the engine&#39;s oil lubrication system with oil, and then passively melts or dissipates upon contact with the oil so as to allow the anti-drainback valve to thereafter close.

This is a continuation-in-part of U.S. patent application Ser. No.07/322,856 filed Mar. 14, 1989 now abandoned.

TECHNICAL FIELD

This invention relates to engine oil filter assemblies and, moreparticularly, to the initial filling of the lubrication system in anewly assembled internal combustion engine wherein there is employed anoil filter with an anti-drainback valve.

BACKGROUND OF THE INVENTION

In a newly assembled internal combustion engine wherein there isemployed an oil filter with an anti-drainback valve, the latter can insome installations block filling or priming of the lubrication systembetween the engine oil pump and the filter and between the filter andthe main oil gallery and, in particular, the hydraulic tappets. As aresult, on initial engine startup and without full priming or filling,there can result discernible noise until the hydraulic tappets arefilled or pumped up. For this reason, it has previously been proposed toprovide a special fill connection between the pump and filter and alsobetween the filter and the hydraulic tappets and also to pre-charge thefilter prior to its assembly. The former provisions require additionalspace and cost, and the latter provision requires a separate fillingoperation and is prone to spillage, particularly where the filter asinstalled has its example, where the filter is mounted horizontally, itis prone to spill from the filter if pre-charging is attempted prior toassembling the filter on the engine. Furthermore, these manners offilling are to be distinguished from the far more costly pre-startengine lubrication systems that charge an engine's lubrication systemprior to every start or on a selective basis.

SUMMARY OF PRESENT INVENTION

The present invention is in a passive system that provides for efficientfilling or priming of the engine's lubrication system without specialaccess or fittings and without having to pre-charge the filter with oil.This is very simply accomplished with the provision of a temporaryanti-drainback valve opener that is inserted during the assembly of theoil filter and operates to hold the anti-drainback valve open duringinitial filling of the engine's lubrication system so that oil duringthe filling process may freely flow through the filter to completelyfill the system. The temporary valve opener is formed of a material thatnormally exists in a solid form but on contact with the engine oiland/or being elevated in temperature dissipates into the oil to allowthe anti-drainback valve to thereafter operate as normal to prevent oilfrom draining back to the oil sump during engine shutdown Preferably,the temporary anti-drainback valve opener is formed of a material thatmelts on contact with oil and also melts on heating within the range ofnormal engine operating temperature. Moreover, the material selected ispreferably of a type that is currently commercially available, ratherthan having to be especially formulated.

It is thus an object of the present invention to provide an engine oilfilter having an anti-drainback valve that is temporarily held open tofacilitate priming of an engine lubrication system.

Another object is to provide an engine oil filter assembly having ananti-drainback valve that is held open during initial filling of anengine's lubrication system and then passively closes to thereafterprovide normal anti-drainback valve operation during engine shutdown.

Another object is to provide a new and improved engine oil filterassembly having an anti-drainback valve that is temporarily held open bya material that melts at an elevated temperature and/or melts on contactwith engine oil to condition the valve for its normal operationfollowing initial filling of the engine's lubrication system through thefilter.

These and other objects, advantages and features of the presentinvention will become more apparent from the following description anddrawings in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial longitudinal sectional view of a conventional oilfilter assembly along with a diagrammatic view of an internal combustionengine lubrication system in which same is connected.

FIG. 2 is a view similar to FIG. 1 but showing the addition of thetemporary anti-drainback valve opener according to the presentinvention.

FIG. 3 is an isometric view showing the filter in FIG. 1 poised over thepreferred form of apparatus for depositing the valve opener in FIG. 2.

Referring to FIG. 1, there is shown an internal combustion enginelubrication system 10 having an oil pan or sump 12 from whichlubricating oil is drawn by a pump 14 and passed through an oil filterassembly 16 prior to delivery to an oil distribution network 18connected to supply the various parts of the engine requiringlubrication, i.e., crankshaft, hydraulic tappets, bearings, etc. The oilfilter 16 in FIG. 1 is of a conventional design and comprises a canister19 which is closed by an end-plate 20 and houses an annular filterelement 22 that is arranged between a plurality of inlets 24 (only oneof which is shown) and a central outlet 26 that is adapted by thethreads there shown to be connected to the distribution network 18. Boththe inlets 24 and threaded outlet 26 are formed in the plate 20 with theoutlet located centrally thereof and the inlets located radially outwardof and angularly about the inlet. Between the inlets 24 and the filterelement 22, there is provided an elastomeric anti-drainback valve 28that normally closes the inlets 24 as assembled and thus when the engineis shut down, but on the development of oil pressure by the pump 14opens to permit oil to pass therethrough. Thereafter, when the engine issubsequently shut down, the anti-drainback valve 26 then normally closesto prevent oil in the filter and upstream thereof from draining backinto the engine's sump.

According to the present invention, a quantity of special grease 30 isdeposited in the filter 16 prior to its assembly on the engine, suchdeposit being in the form of one or more beads injected or otherwiseplaced between the conventional anti-drainback valve 28 and its valveseat 32 on the closure plate 20 as shown in FIG. 2. Such deposit is madethrough one or more of the inlets 24 at one or more places along theanti-drainback valve. The material is preferably that identified as"SLIP COAT" grease "CS #2412" manufactured by Keystone Division ofPenwalt Corporation and normally used for launching ships and off-shoredrill rigs on sliding ways. This material which has the appearance ofyellow-tan paste and belongs to the chemical family of petroleumlubricating grease was discovered to have the characteristics of (a)being firm enough at ambient filter and vehicle assembly temperaturesexceeding 100° F. to hold the anti-drainback valve 28 open against itsinherent elastic closing force but then to melt and allow the valve toclose at a temperature of about 234° F. which falls within the range ofnormal engine operating temperatures of 230-250° F., and (b) meltingupon contact with the oil over a period of time to assure eventual valveclosing over a limited time regardless of the engine reaching its normaloperating temperature. For example, such melting of this material wasfound to completely occur within 2.25 hours maximum. Moreover, thepreferred material has the characteristic of being compatible with theoil such as not to affect the lubricating qualities of the latter nor toresult in adverse deposits on the bearing surfaces and other surfacesinternal of the engine.

Thus with the temporary anti-drainback valve opener 30 applied as shownin FIG. 2 and on assembly of the oil filter on the engine, the engine'soil lubrication system may then be filled through a simple tap 34 in itsmain oil gallery 18 and preferably under pressure and flow through thenormal outlet 26 of the filter to fill the latter and thereafter flowpast the anti-drainback valve to charge the discharge side of the pump.In the particular engine for which the subject filter is adapted, theoil filter itself requires only 1/3 of a pint of oil for filling and theentire main oil gallery including the hydraulic tappets require only atotal of 12/3 pints, and thus the engine's oil lubrication system may bevery rapidly and assuredly filled.

With the preferred temporary valve opener 30 in place and the enginelubrication system initially and thus fully primed, the opener 30immediately starts to dissipate into the oil by contact therewith andthis dissipation by oil contact may go to completion even prior to theinitial engine start up, for example, where first engine start upfollowing the initial oil fill does not occur until after the maximumoil contact melt time. Alternatively, should the engine be startedimmediately after charging with oil, the melting with applied heatcharacteristic of the material then operates to effect the completedissipation when the engine oil reaches its normal operatingtemperature. Moreover, it will be appreciated that the material may alsobe only responsive to melting on temperature buildup in which case asimple oil compatible paraffin or wax material might be used.

Referring to FIG. 3, there is shown apparatus generally designated as 32for depositing the viscous valve opener 30 on a filter assembly line inan accurate, cost effective, rapid manner. The apparatus comprises ahorizontal, cylindrical plate 34 having three (3) vertical tubularinjectors 36 mounted in parallel relationship on the top of the plateand connected therethrough by an internal passage network 38 and thenceby a hose 40 to a pressurized container containing the opener material(not shown). The injectors 36 are closed at their upper end and areangularly spaced at equal radial distances from the plate center so asto align with any three of the oil filter inlets 24 and push the valve28 off its seat 32 when the filter is inserted on the injectors facedown on the plate 34. The injectors 36 each have a radially outwardlyopening outlet port 42 located axially along the injector so as to beopposite the resulting space between the thus lifted valve 28 and itsseat 32. The filter has the normal 0-ring seal 44 for sealing with theengine on assembly thereto and this seal is dampened for such eventualassembly by a cloth type rope/oil soaked pad 46 mounted in a circularupwardly facing groove 48 in the upper face of the plate 34 and centeredtherewith at a radial location corresponding to the filter seal.

On the assembly line an oil filter is placed over the three injectors 36and indexed to align three of the inlets 24 therewith and then pusheddown onto the plate 34 with the oil seal down, thereby lifting the valve28 off its seat 32 with the tops of the injectors 36. With engagement ofthe filter with the plate 34, the oil ring 46 is thereupon dampened witha thin film of oil by the oil pad 46 while opener material 30 is pumpedthrough the injector ports 42 into three angular spaced locations tohold the valve 28 unseated on removal of the filter from this apparatus.

Thus the foregoing description of the preferred embodiment of theinvention has been presented for purposes of illustration anddescription. It is not intended to be exhaustive or to limit theinvention to the precise form disclosed. Obvious modifications andvariations are possible in light of the above teaching. The preferredembodiment was chosen and described to provide the best illustration ofthe principles of the invention and its practical application to therebyenable one of ordinary skill in the art to utilize the invention andwith various modifications as are suited to the particular usecontemplated. All such modifications and variations are within the scopeof the invention as determined by the appended claims when interpretedin accordance with the breadth to which they are fairly, legally andequitably entitled.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. An oil filter assemblyfor an internal combustion engine wherein said oil filter comprises aninlet, an outlet, a filter element located between said inlet andoutlet, an anti-drainback valve located between said filter and saidinlet and normally closed against said valve seat to prevent oil fromdraining out said inlet, the improvement comprising temporary valveopening means between said anti-drainback valve and said seat forholding said anti-drainback valve open during initial filling of theengine lubrication system with lubricating oil thereby to enable fillingof said system, said means formed of a petroleum lubricating grease thatis compatible with the lubricating oil and normally exists in a formfirm enough to initially hold said valve off said valve seat butdissipates on contact with the oil and also melts on initial enginestartup when the lubricating oil reaches a predetermined temperature,whichever dissipation or melting occurs first, thereby allowing thevalve to thereafter close and operate in its normal manner with saidvalve seat.
 2. An oil filter assembly according to claim 1 wherein saidgrease is of a type that remains firm at temperatures exceeding 100° F.and melts at about 230-250° F.
 3. An oil filter assembly according toclaim 1 wherein said grease is of a type that melts upon contact withoil within about 2.25 hours.
 4. An oil filter assembly according toclaim 1 wherein said grease is of a type that remains firm attemperatures exceeding 100° F. and melts at about 230-250° F. and alsomelts upon contact with oil within about 2.25 hours.